The present disclosure relates to gas-enhanced electrosurgical devices. More particularly, the present disclosure relates to structure for aerodynamically manipulating gas flow in a gas-enhanced electrosurgical device.
Devices for arresting blood loss and coagulating tissue are well known in the art. For example, several prior art instruments employ thermic coagulation (heated probes) to arrest bleeding. However, since the probe must come into close contact with the bleeding tissue, the probe may adhere to the eschar during probe removal possibly causing repeat bleeding. Other instruments direct high frequency electric current through the tissue to stop the bleeding. Again, eschar adherence may also be a problem with these instruments. In both types of instruments, the depth of the coagulation is difficult to control.
U.S. Pat. No. 5,207,675 to Canady attempts to resolve certain of the above-noted problems with respect to the prior art by providing a tube-like coagulation instrument in which an ionizable gas is forced through the instrument and ionized by an electrode prior to the gas exiting the distal end of the instrument towards the bleeding tissue.
U.S. Pat. No. 5,720,745 to Farin et al. discloses a coagulation instrument which extends through a working channel of an endoscope and includes an electrode for ionizing a stream of ionizable gas exiting the distal end of the instrument at a rate of less than about 1 liter/minute. As explained in great detail in the Farin et al. specification, the purpose of discharging the gas at a very low flow rate is to effectively cloud the tissue area and create an ionizable gas xe2x80x9catmospherexe2x80x9d to gently coagulate the tissue. In both of the above patents, the gas flow is directed across the electrodes without manipulation.
Using these instruments to treat certain more sensitive tissue sites, may be impractical since the constant and/or direct emission of ionized gas/plasma at the tissue may cause unintended results. Moreover, simply controlling the pressure of the gas from the source may not be effective or yield a desired result.
Thus, a need also exists for the development of a new and effective instrument for controlling and manipulating the flow of gas as it flows through and exits instrument.
The present disclosure relates to a gas-enhanced electrosurgical apparatus. The apparatus includes an elongated flexible tube having a proximal end and a distal end, the proximal end of the tube receives a supply of pressurized ionizable gas and may be configured to be disposed within a working channel of the endoscope. The tube includes at least one aperture and an electrode for ionizing the pressurized ionizable gas prior to the gas exiting the aperture. The apparatus also includes at least one movable incitor/agitator for controlling the flow of the gas such that the gas exits the tube with predetermined flow characteristics, e.g., swirling and/or in a more turbulent manner.
In one embodiment of the present disclosure, the agitator includes a helically-shaped baffle which causes the gas to swirl as it exits the tube. In another embodiment, the agitator includes a rotatable plenum having at least one aperture located therethrough which, under flow conditions, causes the gas to exit the tube in a swirl-like manner. In still another embodiment the agitator includes a pair of elongated ribbons supported within the tube, which, under flow conditions, flutter thus causing the gas to exit the tube in a turbulent manner.